Kaspersky Threats — Backdoor.Win32.VB.lxr

Classe: Backdoor

Os backdoors são projetados para permitir que usuários mal-intencionados controlem remotamente o computador infectado. Em termos de funcionalidade, os Backdoors são semelhantes a muitos sistemas de administração projetados e distribuídos por desenvolvedores de software. Esses tipos de programas mal-intencionados possibilitam fazer qualquer coisa que o autor queira no computador infectado: enviar e receber arquivos, iniciar ou excluir arquivos, exibir mensagens, excluir dados, reinicializar o computador etc. Os programas nessa categoria costumam ser usados a fim de unir um grupo de computadores da vítima e formar uma rede de botnets ou zumbis. Isso dá aos usuários mal-intencionados controle centralizado sobre um exército de computadores infectados que podem ser usados para fins criminosos. Há também um grupo de Backdoors que são capazes de se espalhar através de redes e infectar outros computadores como os Net-Worms. A diferença é que tais Backdoors não se propagam automaticamente (como fazem os Net-Worms), mas apenas com um “comando” especial do usuário mal-intencionado que os controla.

Plataforma: Win32

O Win32 é uma API em sistemas operacionais baseados no Windows NT (Windows XP, Windows 7, etc.) que oferece suporte à execução de aplicativos de 32 bits. Uma das plataformas de programação mais difundidas do mundo.

Família: Backdoor.Win32.VB

No family description

Examples

6E976328B5EC40A7D9F72520C725BBA4
71BE9DBE99802EEE861DEBE4B2F3B5E4
744CE4F0BBEB9D9D225C236B19D5536A
FEBF01DE55E31F7E070217FF2AD14429
0FF7D6FB5E0CEF7D7AB92D8C9208C038

Tactics and Techniques: Mitre*

TA0002

Execution

The adversary is trying to run malicious code. Execution consists of techniques that result in adversary-controlled code running on a local or remote system. Techniques that run malicious code are often paired with techniques from all other tactics to achieve broader goals, like exploring a network or stealing data. For example, an adversary might use a remote access tool to run a PowerShell script that does Remote System Discovery.

T1059.003

Windows Command Shell

Adversaries may abuse the Windows command shell for execution. The Windows command shell (cmd) is the primary command prompt on Windows systems. The Windows command prompt can be used to control almost any aspect of a system, with various permission levels required for different subsets of commands. The command prompt can be invoked remotely via Remote Services such as SSH.

TA0003

Persistence

The adversary is trying to maintain their foothold. Persistence consists of techniques that adversaries use to keep access to systems across restarts, changed credentials, and other interruptions that could cut off their access. Techniques used for persistence include any access, action, or configuration changes that let them maintain their foothold on systems, such as replacing or hijacking legitimate code or adding startup code.

T1547.001

Registry Run Keys / Startup Folder

Adversaries may achieve persistence by adding a program to a startup folder or referencing it with a Registry run key. Adding an entry to the "run keys" in the Registry or startup folder will cause the program referenced to be executed when a user logs in. These programs will be executed under the context of the user and will have the account's associated permissions level.

T1547.014

Active Setup

Adversaries may achieve persistence by adding a Registry key to the Active Setup of the local machine. Active Setup is a Windows mechanism that is used to execute programs when a user logs in. The value stored in the Registry key will be executed after a user logs into the computer. These programs will be executed under the context of the user and will have the account's associated permissions level.

TA0004

Privilege Escalation

The adversary is trying to gain higher-level permissions. Privilege Escalation consists of techniques that adversaries use to gain higher-level permissions on a system or network. Adversaries can often enter and explore a network with unprivileged access but require elevated permissions to follow through on their objectives. Common approaches are to take advantage of system weaknesses, misconfigurations, and vulnerabilities. Examples of elevated access include: SYSTEM/root level, local administrator, user account with admin-like access, user accounts with access to specific system or perform specific function. These techniques often overlap with Persistence techniques, as OS features that let an adversary persist can execute in an elevated context.

T1547.001

Registry Run Keys / Startup Folder

T1547.014

Active Setup

TA0005

Defense Evasion

The adversary is trying to avoid being detected. Defense Evasion consists of techniques that adversaries use to avoid detection throughout their compromise. Techniques used for defense evasion include uninstalling/disabling security software or obfuscating/encrypting data and scripts. Adversaries also leverage and abuse trusted processes to hide and masquerade their malware. Other tactics' techniques are cross-listed here when those techniques include the added benefit of subverting defenses.

T1036

Masquerading

Adversaries may attempt to manipulate features of their artifacts to make them appear legitimate or benign to users and/or security tools. Masquerading occurs when the name or location of an object, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation. This may include manipulating file metadata, tricking users into misidentifying the file type, and giving legitimate task or service names.

T1112

Modify Registry

Adversaries may interact with the Windows Registry as part of a variety of other techniques to aid in defense evasion, persistence, and execution.

T1564.001

Hidden Files and Directories

Adversaries may set files and directories to be hidden to evade detection mechanisms. To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS).

TA0011

Command and Control

The adversary is trying to communicate with compromised systems to control them. Command and Control consists of techniques that adversaries may use to communicate with systems under their control within a victim network. Adversaries commonly attempt to mimic normal, expected traffic to avoid detection. There are many ways an adversary can establish command and control with various levels of stealth depending on the victim's network structure and defenses.

T1095

Non-Application Layer Protocol

Adversaries may use an OSI non-application layer protocol for communication between host and C2 server or among infected hosts within a network. The list of possible protocols is extensive. Specific examples include use of network layer protocols, such as the Internet Control Message Protocol (ICMP), transport layer protocols, such as the User Datagram Protocol (UDP), session layer protocols, such as Socket Secure (SOCKS), as well as redirected/tunneled protocols, such as Serial over LAN (SOL).